For example, in a substrate processing apparatus of semiconductor manufacturing equipment, as disclosed in PTL 1 and PTL 2, a gate valve is installed between a processing chamber and a transfer chamber arranged adjacent to each other so that these chambers are allowed to communicate with each other or, alternatively, to be separated from each other.
The above-described gate valve includes a hollow valve housing having gate openings in side walls of the housing facing away from each other and a plate-shaped valve element in the housing. The valve element is moved in a direction along the side walls and in a direction toward or away from either side wall to open or close the gate opening, thus allowing these gate openings to communicate with each other or to be separated from each other.
The two chambers each have a chamber opening through which a workpiece is loaded into or unloaded from the chamber by a robot arm, for example. The gate valve is airtightly fixed to the two chambers by fixing members, such as bolts, such that the gate openings are connected to the chamber openings.
In coupling two chambers to a gate valve interposed between the chambers, a plurality of gate valves may be arranged adjacent to each other between these chambers and be attached to the chambers.
Chambers have recently been required to be downsized. When a plurality of gate valves are arranged adjacent to each other between two downsized chambers and are fixed to the chambers in the above-described manner, the gap between valve housings of the adjacent gate valves is very small. When the gate valves fixed to one of the chambers are fixed to the other chamber, it is therefore very difficult to tighten a fixing member disposed in the gap between the adjacent valve housings, particularly, in middle part of the gap because it is difficult for a tool to reach the middle part and the tool can be handled in a limited small area in the middle part. Unfortunately, airtightness may fail to be sufficiently achieved between the gate valves and the other chamber.